Share a common alpha value used for displaying disabled state in Harmony

ui/gfx/color_palette.h

Index: ui/gfx/color_palette.h
diff --git a/ui/gfx/color_palette.h b/ui/gfx/color_palette.h
index 35ded5c94ae2a7d2c0d278162953662fe3c792e0..9fae86f7b38591ff94a9e4650e50f8cf3af6e519 100644
--- a/ui/gfx/color_palette.h
+++ b/ui/gfx/color_palette.h
@@ -27,6 +27,10 @@ const SkColor kGoogleGreen700 = SkColorSetRGB(0x0B, 0x80, 0x43);
 const SkColor kGoogleYellow300 = SkColorSetRGB(0xF7, 0xCB, 0x4D);
 const SkColor kGoogleYellow700 = SkColorSetRGB(0xF0, 0x93, 0x00);
 
+// An alpha value for designating a control's disabled state. In specs this is
+// sometimes listed as 0.38a.
+const SkAlpha kDisabledControlAlpha = 0x61;
+
 }  // namespace gfx
 
 #endif  // UI_GFX_COLOR_PALETTE_H_